This invention relates to a process for the determination of the malignant potential of a tumor, and diagnostic kits for carrying out the process. The process is suitable for the sensitive and specific determination of the malignant potential of a tumor.
Neoplastic transformation has been associated with increased synthesis and expression of larger (Asn)-linked oligosaccharides. (L. Warren et al., Biochem. Biophys. Acta. 516, p. 97, 1978; U. V. Santer and M. C. Glick, Biochemistry 18, p. 2533, 1979; J. G. Collard et al., Int. J. Cancer 35, p. 207, 1985; L. Warren et al. Proc. Natl. Acad. Sci. U.S.A. 69, p. 1838, 1972; W.K. Van Beek et al., Nature (London) 253, p. 457, 1975). Such changes have been detected in both rodent (L. Warren et al., Supra; U. V. Santer and M. C. Glick, supra; and, J. G. Collard et al., supra) and human tumor cells (W. K. Van Beek et al., supra) transformed by chemical mutagens (L. Warren et al., supra), mutagenic viruses (U. V. Santer and M. C. Glick, supra), or by transfection with DNA obtained from neoplastic cells (J. G. Collard et al., supra). The change in size in a number of studies has been attributed to an increase in sialic (neuraminic) acid content of the structures (L. Warren et al., Proc. Natl. Acad. Sci. U.S.A., 69, p. 1838, 1972; W. K. Van Beek et al., supra; and L. Hunt and S. E. Wright, Biochem. J. 229, p. 481, 1985). Increased branching may also contribute to the transformation related increase in sialic acid (K. Yamashita et al., J. Biol. Chem. 259, p. 10834, 1984; M. Pierce and Arango J., J. Biol. Chem. Cancer Res. 44, p. 3730, 1984). Branching of complex Asn-linked oligosaccharides to produce tri, tri'- and tetra-antennary structures has been associated with the action of UDP-GlcNAc: .alpha.-D-mannoside .beta.1; 4N-acetylglucosaminyltransferase (GlcNAc transferase IV) and UDP-GlcNAc: .alpha.-D-mannoside .beta.1, 6N-acetylglucosaminyltransferase (GlcNAc transferase V) (H. Schachter, Biochem. Cell Biol. 64, p. 163, 1986 and A. Gleeson and H. Schachter, J. Biol. Chem. 258, p. 6162, 1983).
Lectins have been used as histochemical probes to study cell surface carbohydrates on tumor cells. As to the cytochemistry and histochemistry of lectins, reference may be made to the general review by Damjanov, Lab. Invest. 57, p. 1, 1987). H. Debray et al. (Int. J. Cancer, 37, p. 607, 1986) studied the expression of total cellular glycopeptides on human uroepithelial cell lines derived from transitional-cell carcinoma or from normal uroepithelium. H. Debray et al., used concanavalin A (Con A) and Lens culinaris agglutinin (LCA)- Sepharose to separate and identify the glycopeptides. U. V. Santer et al. (Cancer Res. 44, p. 3730, 1984) using immobilized lectins, Con A, leukoagglutinating phytohemagglutinin (L-PHA) and erythroagglutinating phytohemagglutinin (EPHA), reported altered glycosylation of the membrane glycoproteins of 2 different transformants generated by transfection of human DNA from cell lines with different oncogenes.
There have been a number of studies where lectin binding has been found to correlate with invasiveness and malignancy of specific tumors. C. Limas and P. Lange (Cancer 58, p. 1236, 1986) disclosed a correlation between the expression of Arachis hypogaea (peanut agglutinin) (PNA) binding sites on the surface of bladder carcinoma cells with the invasiveness and malignancy of these tumors. M. Helle & K. Krohn (Vichows Arch [A] 410, p. 23, 1986) found that expression of PNA receptors on breast carcinoma cells appears to be associated with the expression of estrogen receptor on these cells. However, no significant correlation has been found between PNA receptor, histologic grade and pathologic stage of tumors. (W. Bocker et al., Virchows Arch. [A] 403, p. 149, 1984 and R. A. Walker, Histopathology 9, p. 1121, 1985). Ulex europaeus agglutinin (UEA-1) has been shown to be a reliable and useful marker for endothelial cells and tumors of vascular origin (H. Holthofer et al., Lab Invest. 47, p. 60, 1982, Am. J. Clin. Pathol. 79, p. 32, 1983, and Arch Pathol. Lab Med. 108, p. 129, 1984). Helix pomatia lectin (HPA) binding to histological sections of primary human breast carcinoma was associated with poor prognosis and short survival time (Leathem, A. J. & Brooks, S. A., Lanceti, p. 1054, 1987).
A method has been described by M. Adachi for determining tumor-associated glycolinkage (TAG) including glycoproteins, glycopeptides, glycolipids and/or sugars having an N-acetyl-D-galactosamine (AG) or L-Fucose terminus in body fluid of mammals using AG-binding lectin or L-fucose binding lectin (U.S. Pat. No. 4,455,380). Adachi has also described a method for determining TAG including glycoproteins, glycopeptides, glycolipids and/or sugars containing galactose-(.beta.1-3 or .beta.1-4)-N-acetylglucosamine or galactose-(.beta.1-3 or .beta.1-4)-N-acetylgalactosamine terminus, in body fluid of mammals using lectins which can combine specifically with galactose-(.beta.1-3 or .beta.1-4)-N-acetylglucosamine or galactose-(.beta.1-3 or .beta.1-4)-N-acetyl-galactosamine. It is disclosed in the patents that the methods can be used to detect the presence or absence of cancerous cells, to check the degree of proliferation and to determine the prosperity and decay of cancerous cells. There is no indication that the methods can be used for differentiating metastatic and non-metastatic behaviour which is of considerable importance for diagnosis and prognosis.